/*

 * Licensed to the Apache Software Foundation (ASF) under one

 * or more contributor license agreements.  See the NOTICE file

 * distributed with this work for additional information

 * regarding copyright ownership.  The ASF licenses this file

 * to you under the Apache License, Version 2.0 (the

 * "License"); you may not use this file except in compliance

 * with the License.  You may obtain a copy of the License at

 *

 *     http://www.apache.org/licenses/LICENSE-2.0

 *

 * Unless required by applicable law or agreed to in writing, software

 * distributed under the License is distributed on an "AS IS" BASIS,

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.

 * See the License for the specific language governing permissions and

 * limitations under the License.

 */

package com.bff.gaia.unified.sdk.fn.stream;



import com.bff.gaia.unified.vendor.grpc.v1p13p1.io.grpc.stub.StreamObserver;



/**

 * A {@link StreamObserver} which provides synchronous access access to an underlying {@link

 * StreamObserver}.

 *

 * <p>The underlying {@link StreamObserver} must not be used by any other clients.

 */

public class SynchronizedStreamObserver<V> implements StreamObserver<V> {

  private final StreamObserver<V> underlying;



  private SynchronizedStreamObserver(StreamObserver<V> underlying) {

    this.underlying = underlying;

  }



  /**

   * Create a new {@link SynchronizedStreamObserver} which will delegate all calls to the underlying

   * {@link StreamObserver}, synchronizing access to that observer.

   */

  public static <V> StreamObserver<V> wrapping(StreamObserver<V> underlying) {

    return new SynchronizedStreamObserver<>(underlying);

  }



  @Override

  public void onNext(V value) {

    synchronized (underlying) {

      underlying.onNext(value);

    }

  }



  @Override

  public synchronized void onError(Throwable t) {

    synchronized (underlying) {

      underlying.onError(t);

    }

  }



  @Override

  public synchronized void onCompleted() {

    synchronized (underlying) {

      underlying.onCompleted();

    }

  }

}